Furnace grate



Nov. 17l 1925.

J. STEELE Er AL A FURNACE GRATE 'Filed laren 2o. 192s Patented Nov. 17, 1925.

UNITED'STATES PATENToFFicE.

Louis JOHN STEELE AND EDGAR EEosTIcK KENT, oE EoETsiiioUTH,` AND GEORGE ALBERT MADDEN, E soUTHsEA, ENGLAND.

y EURNAcE GEATE.

Application filed` March 20, 1923. Serial No. 626,353.

To all whom t may concern.'

Be it known that we, Louis JoHN STEELE, EDGAR Fiios'rioii KENT, and GEORGE ALBERT MADDELJ, subjects of the King of Great Britain and Ireland, residing, respectively, at The Parade, H. M. Dockyard, Portsmouth, in the county of Hants, England, 49 Ophir Road, Portsmouth, in'the county of Hants, England, and 51 Winter Road, Southsea, in the county of" Hants, England, have invented `certain new and useful Improvements Relating to Furnace Grates, of which the following is a specification.

This invention primarily relates to stokers of the travelling grate type in which longitudinally or transversely disposed grate bars are carriedwithin so called caps or frames that are transversely disposed in parallel lines and arereinovably secured to transversely disposed bars connected together to form an endless conveyor, the uppermost part of which `forms the grate on which the fuel is burnt, the conveyor being periodically moved whereby the fuel is received on the grate as it `passes into the furnace and carries the fuel forward towards the end of the combustion chamber where the clinker and ashes are discharged.

In such a type of stolier, the air admitted in any desired manner and at any desired point passes beneath the grate, and then through the interstices between the grate bars in the caps or frames. Owing to the severe and destructive conditions which obtain when the coal is burnt on metallic sui'- faces, the grate'bars in operation frequently become fused together and tolthe frames or caps in which they are carried, with the rcsult that the supply of air becomes inadeuate and thus in the movement of the grate t rough the furnace, the fuel is not completely consumed, whereby waste of fuel and inefficiency result.

The invention has for its object to avoid this disadvantage by the provision of the bars integral with the so-called caps or frames and of such a form that fusion of the metal of the bars is avoided.

Thus accordingr to the invention the grate hars are integrally formed with the caps or frames and the interstitial spaces between the bars, and between the bars and the parallel disposed ends of the frame, gradually increase in width from the bottom to the 'l top or alternatively are made parallel to supporting bars suit certain grades of coal, so that thus all these spaces diverge upwardly and the air passingthrough them is widely diffused. `In intermediate positions transverse to the grate bars and also on the opposite sides of the cap or frame, partitions or walls are integrally provided which protrude downwardly to form strengthening ribs which `also increase the heat radiating and conducting y surfaces, by which the integral frames and bars are kept cool.

Furthermore according to the invention the tops of the bars are luted.

By .such means it will be understood that the air in passing up through the interstitial spaces between the bars is widely diffused, the radiating surface is increased and the burning of the bars is prevented.

The invention is widely applicable to furnace grates.

A construction of furnace grate provided according to the invention is illustrated in the accompanying drawings in which- Figure 1 is a detail elevation showing two of the caps or frames in which are disposed the grate bars.

Figure 2 is a Figure l. i

Figure 3 is a transverse section on the line X X of Figure l.

It will be understood that in carrying the invention into effect the caps or frames are mounted upon any desired construction of endless supporting chain or carrier to forni the travelling grate. In the. construction of plan view corresponding to `endless chain orcai'rier diagraminatically represented in the drawingsa series of pairs of links a pivoted upon spindles Z) serves to carry transversely `disposed cap or frame c. Each of the said bars c supports a series of the caps or frames Z in `which are integrally formed the grate bars e in accordance` with the invention.. Each cap or frame d is provided with a downwardly extending lug l1 in which is formed a square hole for the reception of the square shank of a bolt f by which the cap or frame is secured in position upon the supporting bar c. The latter is advantageously formed with upstanding lugs g of rectangular forni adapted to lit within correspondingly shaped recesses /1J formed in the lower edges of the downwardly depending portions of the adjacent caps or frames d.

Each cap or frame d is formed with a series of grate bars e extending longitudinally, the said bars being of a cross-section increasing from the lower edge to the upper surface and being disposed in such manner that the interstitial spaces z' between the adjacent bars also gradually increase in width from the bottom to the top. By reason of what may be termed the radial disposition of the grate bars in each cap or frame, the air passing through the grate from beneath is well diffused or distributed in a fan-wise manner through the fuel. Transverse partitions y' are formed at intervals across the width of the caps or frames and serve to strengthen and support the grate bars. They are advantageously extended downwards as at jl to give increased strength and also to increase the heat radiating surface. The upper faces of the grate bars e are advantageously fiuted. This serves to permit the collection of dust thereon and thus to prevent clinker from l,directly adhering to the bars. Any clinker formed is readily removed by reason of the intermediate layer of dust. Each of the cap or frame supporting bars c carries a series of the caps or frames extending the length of the bar which is determined according to the width of the furnace to which the grate is applied. The caps or fra-mes are identical with the exception of those at each end of the series which are specially formed for this purpose.

As indicated in Figure 1 the end cap or frame is extended and provided with a massive end wall la having an inner face formed to a hyperbolic curve or surface and an outer face formed with an inclined surface Z upon the depending portion which may serve to rest upon guides provided at the side of the grate. The said end caps or frames are also provided with rectangular recesses m of the full size to receive the corresponding upstanding lug g of the supporting bar.

It will be understood that the invention is not limited in application to any particular type of travelling grate, nor to any particular means of supporting and moving' the caps or frames, nor to the manner of mounting them upon the transverse supporting bars hereinbefore described. The invention is further applicable with advantage to the construction of fixed grates.

We claim:

l. A furnace grate of the travelling type, comprising grate elementsv consisting of frames having integral straight end walls and a plurality of integral transversely disposed grate bars extending between said end walls, said transversely disposed grate bars being wider at the top than at the bottoni, and having the interstitial spaces between them diverging outwardly towards opposite sides upwardly, and a conveyor upon the transversely disposed members of which the said grate elements are supported in transverse series and members disposed at one side of said frames and integral therewith by which said frames are supported upon said conveyor, substantially as described.

2. A furnace grate of the travelling type, comprising grate elements consisting of frames having integral straight end walls and a plurality of integral transversely disposed grate bars extending betweenwsaid end walls, said transversely disposed grate bars being wider at the top than at the bottom and having the interstitial spaces between them diverging outwardly towards opposite sides upwardly, and having their upper faces grooved, and a conveyor upon the transversely disposed members of whichthe said grate elements are supported in transverse series and members disposed at one side of said frames and integral therewith by which said frames are supported upon said conveyor, substantially as described.

3. A furnace grate of the travelling type, comprising grate elements consisting of frames having integral straight end walls and intermediate partitions, and a. plurality of integral transversely disposed grate bars extending between said end walls, said transversely kdisposed grate bars being wider at the top than `at thev bottom and having the interstitial spaces between them diverging 4outwardly towards opposite sides upwardly,

the said partitions extending downwardly beyond the said grate bars, and a conveyor upon the transversely disposed members of which the said grate elements .are supported in transverse series, substantially as described.

yLOUIS JOHN STEELE.

GEORGE ALBERT MADDEN. EDGAR FROSTICK KENT.

IOL 

